Study Explores Decision-making Abilities in Bipolar Disorder Patients

Increased activity in the prefrontal cortex and nucleus accumbens explained why bipolar disorder patients took larger gambling risks.

Increased activity in the prefrontal cortex (PFC) and nucleus accumbens explained why bipolar disorder patients took larger gambling risks, according to a study published July 9 in Brain.

By conducting functional magnetic resonance imaging (fMRI) on 20 bipolar disorder patients and 20 controls while they performed a roulette task, researchers at the University of Manchester (UOM) and University of Liverpool (ULIV) in the United Kingdom aimed to discern whether impaired decision-making in affected patients was associated with bipolar disorder.

To preserve the study’s integrity, researchers eliminated candidates who recently suffered from alcoholism and substance abuse or had taken antipsychotic medications.

The researchers discovered a distinction in how bipolar disorder and healthy patients process risks and goals. Participants with bipolar disorder experienced greater activity in their dorsolateral-PFC when making riskier bets, while it was the opposite for control patients, according to the investigators. Furthermore, they noted that bipolar subjects’ ventral striatum activity spiked when anticipating rewards.

According to a UOM release, the findings indicated the relevance of the “pleasure center” in nucleus accumbens, which is responsible for reflexively seeking rewards prior to conscious thought. However, for bipolar patients, the nucleus accumbens is considerably more active than in healthy individuals.

“The greater buzz that people with bipolar disorder get from reward is a double-edged sword,” Wael El-Deredy, professor at UOM’s School of Psychological Sciences and contributor to the study said in a statement. “On the one hand, it helps people strive towards their goals and ambitions, which may contribute to the success enjoyed by many people with this diagnosis. However, it comes at a cost: these same people may be swayed more by immediate rewards when making decisions and less by the long-term consequences of these actions.”

In light of their findings, the investigators claimed their results could help understand bipolar disorder and other impulsivity disorders and provide appropriate treatment.

“These markers may be useful in evaluating both kinds of interventions,” the authors concluded. “In particular, interventions that bolster dorsolateral PFC-mediated cognitive control may be an important direction for future research.”